可再生能源供电无线通信的最优链路传输策略

[摘要] 利用可再生能源为无线通信发射机供电，可以实现绿色通信的无线传输。认为通信发射机由可再生能源供电，并综述了点对点衰落信道的吞吐率最大化问题、中断概率最小化问题。首先，针对吞吐率最大化问题，考虑信道相干时间与能量相干时间相同的情况，提出了基于阈值的最优发射功率分配策略，给出了阈值的高效计算方法，并将结果推广到更一般的情形。然后，针对中断概率最小化问题，考虑信道相干时间大于或等于能量相干时间情况，证明了最优分配功率策略具有“存储-发射”的结构。最后，通过数值结果和仿真验证算法的有效性。

[关键词] 能量收集；吞吐率；中断概率；衰落信道；最优功率分配

[Abstract] Wireless transmitter supplied by the renewable energy sources is seen as a way to achieve green communication. The throughput maximization and the outage probability minimization problems in point-to-point fading channels with the transmitter powered by the renewable energy are studied in this paper. First, the throughput maximization problem for the case that the duration of the channel coherence (CC) slot is the same as that of the energy coherence slot is considered, and a “threshold-based” optimal energy allocation is proposed. An efficient numerical algorithm is then proposed to obtain the threshold, and then the results are extended to the case that the duration of the CC slot is less than that of the energy coherence slot. Then, for the outage probability minimization problem, the case that duration of the CC slot is less than or equal to that of the energy coherence slot is considered and its optimal power allocation owns the “save-then-transmit” structure is proved. At last, the numerical results are given to verify the effectiveness of the algorithm.

[Keywords] energy harvesting; throughput; outage probability; fading channel; optimal power allocation